Integrating sensing systems into thermostat housing in manners facilitating compact and visually pleasing physical characteristics thereof

Abstract

An occupancy sensing electronic thermostat is described that includes a thermostat body having a curved exterior front surface, a dot matrix display mounted within the body viewable by a user in front of the front surface, a passive infrared sensor for measuring infrared energy and a shaped Fresnel lens having a smooth outer surface that extends across only a portion of the exterior front surface of the thermostat body. The Fresnel lens is shaped and curved so as to conform to and form a part of the curved exterior front surface of the thermostat body. A second downwardly directed passive infrared sensor can also be provided to aid in the detection of an approaching user who intends to interact with the thermostat.

What is claimed is: 
     
       1. An occupancy sensing electronic thermostat comprising:
 a thermostat body having a curved exterior front surface; 
 a dot matrix display mounted within the body viewable by a user in front of the front surface; 
 a passive infrared sensor for measuring infrared energy; 
 a shaped Fresnel lens member having a smooth outer surface that extends across only a portion of the exterior front surface of the thermostat body, the Fresnel lens member being shaped and curved so as to conform to and form a part of the curved exterior front surface of the thermostat body, the Fresnel lens member including at least one Fresnel lens portion comprising a plurality of facets formed on an interior surface of the Fresnel lens member to focus infrared energy onto the passive infrared sensor; 
 a first temperature sensor positioned behind the Fresnel lens member, for making temperature measurements used for a calculation of ambient temperature; 
 a second temperature sensor positioned within the thermostat body in a location closer than the first temperature sensor to one or more heat generating components within the thermostat body, wherein the calculation of ambient temperature is based at least in part on a comparison between measurements from the first and second temperature sensors; and 
 a microprocessor programmed to detect occupancy based at least in part on measurements made by the passive infrared sensor. 
 
     
     
       2. A thermostat according to  claim 1  wherein the Fresnel lens member includes a plurality of lenslets, each of which is a Fresnel lens having facets formed on the inner surface of the Fresnel lens member. 
     
     
       3. A thermostat according to  claim 1  wherein the thermostat is wall mountable. 
     
     
       4. A thermostat according to  claim 3  wherein the Fresnel lens member is mounted beneath the dot matrix display such that it is below the display when the thermostat is mounted on a wall. 
     
     
       5. A thermostat according to  claim 1  wherein the thermostat body is disk-shaped, and wherein the curved exterior front surface is spherical and has a radius of curvature of greater than 100 mm. 
     
     
       6. A thermostat according to  claim 1  wherein the Fresnel lens member is shaped and positioned so as to provide the passive infrared sensor with a vertical field of view skewed downwards from horizontal when the thermostat is wall mounted. 
     
     
       7. A thermostat according to  claim 1  wherein the exterior front surface of the thermostat is substantially free of vents and grilles. 
     
     
       8. An occupancy sensing electronic thermostat comprising:
 a thermostat body having a curved exterior front surface; 
 a dot matrix display mounted within the body viewable by a user in front of the front surface; 
 a passive infrared sensor for measuring infrared energy; 
 a shaped Fresnel lens member having a smooth outer surface that extends across only a portion of the exterior front surface of the thermostat body, the Fresnel lens member being shaped and curved so as to conform to and form a part of the curved exterior front surface of the thermostat body, the Fresnel lens member including at least one Fresnel lens portion comprising a plurality of facets formed on an interior surface of the Fresnel lens member to focus infrared energy onto the passive infrared sensor; 
 a microprocessor programmed to detect occupancy based at least in part on measurements made by the passive infrared sensor; and 
 a mechanically rotatable annular ring surrounding the display and the Fresnel lens member, the annular ring being rotatable around a front-to-back axis of the thermostat, and said annular ring is inwardly pressable along a direction of the front-to-back axis. 
 
     
     
       9. An occupancy sensing electronic thermostat comprising:
 a thermostat body having a curved exterior front surface; 
 a dot matrix display mounted within the body viewable by a user in front of the front surface; 
 a passive infrared sensor for measuring infrared energy; 
 a shaped Fresnel lens member having a smooth outer surface that extends across only a portion of the exterior front surface of the thermostat body, the Fresnel lens member being shaped and curved so as to conform to and form a part of the curved exterior front surface of the thermostat body, the Fresnel lens member including at least one Fresnel lens portion comprising a plurality of facets formed on an interior surface of the Fresnel lens member to focus infrared energy onto the passive infrared sensor; 
 a microprocessor programmed to detect occupancy based at least in part on measurements made by the passive infrared sensor and; 
 a second passive infrared sensor for measuring infrared energy, the Fresnel lens member being shaped and the second passive infrared sensor being positioned such that it is provided with a substantially downwardly directed field of view when the thermostat is wall mounted, and the microprocessor being further programmed to detect an approaching user that will likely directly interact with thermostat based at least in part on the measurements made by the second passive infrared sensor. 
 
     
     
       10. A thermostat according to  claim 9  wherein a state of one or more processors within the thermostat is changed from an inactive state to an active state based on detections by the microprocessor of an approaching user, thereby enhancing responsiveness to a user while conserving energy at times when user interaction is unlikely. 
     
     
       11. A thermostat according to  claim 9  wherein the second passive infrared sensor mounted above the passive infrared sensor, and the second passive infrared sensor is tilted downwards so as to enhance detection of an approaching user. 
     
     
       12. An occupancy sensing electronic thermostat for controlling an HVAC system within an enclosure, the thermostat comprising:
 a first passive infrared sensor mounted within the thermostat so as to measure infrared energy tending to indicate occupancy within the enclosure; 
 a second passive infrared sensor mounted within the thermostat so as to measure infrared energy tending to indicate a user is likely to interact with the thermostat; and 
 one or more energy consuming thermostat components that have active and inactive states, the one or more components consuming less energy the inactive states than the active states, wherein the transition from inactive to active states is based at least in part on measurements from the second passive infrared sensor. 
 
     
     
       13. A thermostat according to  claim 12  further comprising a shaped Fresnel lens member having including at least one Fresnel lens to focus infrared energy onto the first and second passive infrared sensors. 
     
     
       14. A thermostat according to  claim 13  wherein the Fresnel lens member is shaped and the second passive infrared sensor being positioned such that it is provided with a substantially downwardly directed field of view when the thermostat is wall mounted, such that an approaching user that will likely directly interact with thermostat can be detected based at least in part on the measurements made by the second passive infrared sensor. 
     
     
       15. A thermostat according to  claim 14  wherein the second passive infrared sensor mounted above the first passive infrared sensor, and the second passive infrared sensor is tilted downwards so as to enhance detection of an approaching user. 
     
     
       16. A thermostat according to  claim 12  wherein the one or more energy consuming components includes a microprocessor. 
     
     
       17. A thermostat according to  claim 12  wherein the one or more energy consuming components includes a dot matrix display. 
     
     
       18. A thermostat according to  claim 12  wherein the one or more energy consuming components includes radio communication components. 
     
     
       19. An occupancy sensing electronic thermostat comprising:
 a thermostat body having a curved exterior front surface; 
 a dot matrix display mounted within the body viewable by a user in front of the front surface; 
 a first passive infrared sensor mounted within the thermostat so as to measure infrared energy tending to indicate occupancy within the enclosure; 
 a second passive infrared sensor mounted within the thermostat so as to measure infrared energy tending to indicate a user is likely to interact with the thermostat; 
 a shaped Fresnel lens member having a smooth outer surface that extends across only a portion of the exterior front surface of the thermostat body, the Fresnel lens member being shaped and curved so as to conform to and form a part of the curved exterior front surface of the thermostat body, the Fresnel lens member including a plurality of Fresnel lens portions each comprising a plurality of facets formed on an interior surface of the Fresnel lens member to focus infrared energy onto the first and second passive infrared sensors; and 
 one or more energy consuming thermostat components that have active and inactive states, the one or more components consuming less energy the inactive states than the active states, wherein the transition from inactive to active states is based at least in part on measurements from the second passive infrared sensor.